Hand drill



May 1, 1928. 1,667,976

0. E. LINDBERG HAND DRILL Filed Nov. 10. 1926 60 i \Q "-6 w a 4 I 13\ oI 1 Carl E, Lz'ndbery 20 the turning actionof the Patented May 1, 1928.

CARL E. LINDBERG, OF SILVERDALE, WASHING-TON.

ICE

HAND DRILL.

Application filed November 10, 1926. Serial No. 147,408.

M invention relates to drills and particular y to the type of smalldrill which is intended to be held in and operated by the hand.

The object of my invention is to provide a drill, particularly of thistype, with means whereby it is provided with a store of inertiasuflicient, to enable it to overcome, without serious difficulty,relatively small obstructions to itsturning, such for instance as occurwhen a drill works through a thin sheet of metal.

My invention consists essentially in pro viding and mounting upon thedrill afly wheel geared to the turning parts of the drill, so as to havea relatively high rate of rotatiomwhereby whenever the drill strikesanything which tends to stop it, the inertia of the rapidly revolvingfly wheel will assist hand to cause the bit to continue turning, therebyproducing a more uniform and smooth action.

The particular parts and combinations of parts which I believe to benew, and upon which I desire a patent, will be hereinafter particularlyset forth in the claims.

In the accompanying drawings I have shown a construction in which myinvention has been incorporated, the same being applied to a small handdrill.

Figure 1 shows such a drill having my invention incorporated therein,with the major part of its mechanisms in section.

Figure 2 is a face view of the same drill.

In the drawings, 1 represents a frame which may be of any suitableconstruction, which provides the proper bearing and suport for thevarious parts of the drill. This rame is provided with a handle 10 ofordinary construction, by which it may be held. It is also provided witha bit-carrying shaft 11 journaled therein, and provided with anysuitable means for holding the drill.

Secured upon and to turn with the bitcarrying shaft 11 are two gears 2and 3. The gear 2 is a small gear and the gear 3 a much larger gear.These are bevel gears and mesh, respectively, with the gears and 30,which are, respectively, large and small gears, each meshing with itscomplemental gearas 2 and 3, that is, the small gear of each set mesheswith the large gear of the other set.

The gears 20 and are mounted to turn about the same axis, this beingrepresented by the shaft l0. They are, however, tur able independentlyof each other, The gear 30 has a fly wheel l secured thereto. Aprotective and enclosing casing 5 is provided for this fly wheel, whichcasing also serves as the mountor carrier for the large gear 20 of thesecond set. The crank arm 6 and handle by which the drill is operated,is also secured to the casing 5.

The first set of gears consisting of the pinion 2 and gear 20correspondwith the two gears which are employed in the ordinary handdrill. The second set of gears consisting of the gear 3 and pinion 30are added gears which are employed in order to rotatively connect thefly wheel 4 with the bitcarrying shaft 11, and also for the purpose ofsecuring a higher rate of rotation for the fly wheel. Itis evident thatthe inertia of the fly Wheel depends to a very large extent upon itsspeed of rotation, and for this reason it is desirable to have it turnat a rela tively much higher rate than does the bitcarrying shaft 11.

The method of mounting the fly wheel illustrated does not varymaterially, change the size of the drill or make it cumbersome to handleor operate. It will be found that with such a fly wheel the drill may beused to drill through such material as thin plates of metal without theobjectionable effect usually found, due to the drill forcing its waythrough the sheet before it has entirely cut away all of the material.

It' is evident that many of the details of construction might be changedwithout in any essential way changing the principle of my invention.This principle does not include merely the mounting of a fly wheel upona drill, but the mounting of a fly wheel upon a drill. in such a way astomake it adapted for application to hand drills of small size, and soas to protect the mecha nisms essential thereto from injuring the user.

What I claim as my invention is:

1. In a hand drill, in combination, a rotative bit-carrying shaft, asmall and a large bevel gear fixed to said shaft, complemental small andlarge gears independently turnable about the same axis and meshing eachwith its respective one of the first pair of gears, a fly wheel securedto the small gear of the second pair, a casing enclosing said fly wheelI and fixed to the larger gear of the second pair, and a turning crankfixed to said casing.

2. In a hand drill, a frame, a bit-carrying shaft journaled in saidframe, a small and a large bevel gear secured to said shaft, a drum bodyhaving thereon a large bevel gear meshing with the smaller gear upon thebit-carrying shaft, said drum enclosing both of the said gears, atransverse shaft carried by the frame and having the drum journaledthereon, a fly wheel journaled upon the same shaft and positioned Withinthe drum and adjacent to its bottom, and a small gear secured to saidfly wheel and meshing with the larger gear upon the bit-carrying shaft.

3. A drill comprising a frame, a bit-carrying shaft journaled in theframe, a large and a small gear secured to said shaft, a journal shaftmounted upon the frame at right angles to the bit-carrying shaft at oneside only thereof, a small and a large gear independently journaled uponsaid journal shaft and at the same side of the bitcarrying shaft, saidlatter gears meshing each with its complemental one of the first pair, afly wheel secured to the small gear of the second pair, a drum securedto the large gear of the second pair and enclosing the fly wheel and thesecond pair of gears, and means for applying power to turn said drum andthe connected gears.

4-. The cmnbination in a hand drill, of a bit-carrying member, a flywheel geared to the bit-carrying member to turn at a higher rate thanthe bit-carrying member, an operating crank and gears relativelyconnecting the crank with the bit-carrying member independently of thefly wheel connection therewith, and a pl'olll-ittllvt casing for all ofsaid gears secured to and connecting the crank and the driving member ofthe bildriving gears.

Signed at Silver-dale, Kilsap County, lVashington, this 3rd day ofNovember, 1926.

CARL E. LINDBERG.

